Alexander McCall Smith, the best-selling author of The No 1 Ladies’ Detective Agency, will introduce gay characters into his new books.

The new gay characters will appear in Mr McCall Smith’s 44 Scotland Street and Sunday Philosophy Club series.

Mr McCall Smith, who is a dedicated supporter or HIV charities, said:

“I take the view that gay people should be treated in fiction in the same way as everyone else – with the courtesy and respect we should all show to each other.

“I do not like hurtful or cruel portrayals of any group.

“I have no plans to change the general tenor of my books, which are read, I believe, by a very wide range of people who no doubt have all sorts of views on all sorts of subjects.”

In Corduroy Mansions, Mr McCall Smith’s latest work, he portrays a gay character who realises that he is actually straight.

Gay rights activist Peter Tatchell said: “I guess a lot of writers and publishers have been afraid of alienating readers who they assumed to be homophobic.

“In recent years, the taboo has begun to fade.

“By integrating gay characters and themes into otherwise mainstream novels it can help promote understanding and acceptance.”

Mr McCall Smith’s first No 1 Ladies’ Detective Agency novel became a best-seller in 1998, and since then he has written five more of the series.